Manufacture of damped bellows



June 29, 1948. J. v. GIESL ER 2,444,192

- I MANUFACTURE OF nmrnn BELLOWS Original Filed May 11, 1942 I 2Sheets-Sheet 1 June 29, 1948.

J. v. GIESLER 2,444,192

MANUFACTURE OF DAMPED BELLOWS Original Filed May 11, 1942 2 Sheets-Sheet2 Fi'QII H6112. HQ.I3. F2914. [915.

MANUFACTURE OF DAMPED BELLOWS Jean V. Giesler, Knoxville, Tenn, minor toBobertshaw-Fulton Controls Company, a corporatlon of Delaware Originalapplication May 11, 1942, Serial No.

I 442,514, now Patent No. 2,434,194, dated Jam.

. nary 20, 1848. Divided and this application May 29, 1944, Serial No.531,901

This invention relates to a method of making a damping bellows.

Metallic bellows when subjected to vibration whose frequency is close tothe natural period of the bellows have been found to have a mate- I toillustrate diagrammatically the formation of rlally shortened life. andthis has interfered to the elements shown in Figs. 6 to respectively.some extent with their use where they are likely Referring first to Fig.i, ll! designates a bellows to be subjected to rather severe vibrations,as on of any suitable size, construction and material, aircraft engines.Various mechanical damping here shown as in the form of a one-pieceexmeans havebeen proposed, but while they were 10 pansible andcollapsible corrugated tubular wall successful in reducing the amplitudeof vibration having one end suitably attached to an end memthe bellows,t ey have had t defect t t ey bar I I and its opposite end suitablyattached to have relied to a greater or lesser extent on the a flange i2on a casing element I I. As shown, action of friction, and as frictionvaries under the bellows I0 is mounted in a tubular housing differentconditions the use of friction to effect I4 having a. reentrant wall Itwhich is aperd pi s s resulted in err ic op r ion tured at its inner endto siidingl receive a post In y application Serial O- 4 2,514, filed Mayi6 attached to or integrally formed on the mov- 1942, H W 2. ted ableend member ll. Post I! is connected to any 1948, r p g f bellows, ofwhich this apsuitable element to be controlled and in the form plicationis a division, I have disclosed and 20 ho n a coil spring I! isinterposed between a claimed a novel damping bellows and method offlange or collar I 8 on the post I 6 and the inner damping wherein abellows is provided with fins end of the reentrant wall l5. As thepresent inwhich are adapted to utilize the princi le of a ven'tion maybe embodied in any suitable bellows dash p to effect p structure appliedto any suitable operating or It is an object of this invention toprovide a controlling mechanism, the means for mounting novel method ofmaking a bellows structure that and connecting the bellows constitute nopart is adapted to eifect such damping action. of the present invention,and said mounting and Another object of this invention is to providenecting means are therefore to be taken as ila novel method of making abellows having damplustratlve onlying fins integrated with thecorrugations thereof. 80 In conformity w th t present invention. 011

Another object of this invention is to provide or more of thecorrugations 20 of the belows ill, a novel method of making dampingelements. and preferably all of them, have integrated there- Otherobjects will appear as the description of with in any suitable wayannular fins 2| which the invention proceeds. project radially andcircumferentially beyond the The invention is capable of receiving avariety periphery of the bellows. Surrounding the peof expressions, oneof which is illustrated on the r phery of the fins 2| is a confiningWall, here accompanying drawings, but it is to be expressly shown as thetubular wall I4 of the encasing understood that the drawings are fOrpurposes of Structure. and Said wall s 80 disposed w illustration only,and are not to be construed as p t to sai fins as to make a small but Pa definition of the limits of the invention, refer- 40 determinedclearance with the periphery of said ence being had to the appendedclaims for that fins- T e space between the bel ws 0 and t purpose.confining wall i4 is filled 'with a suitable liquid, Referring in detailto the drawings, wherein the. preferably oil, said oil extending intothe chamber same reference characters are employed to desig- 22 a o e es as illustrated With a s nate corresponding parts in the severalfigures, cient space 23 thereabove to provide for the move- Fig. 1 is anaxial section through a bellows ment of the oil next to be explained.structure provided with damping means in con- At any given position ofthe corrugations of formity with the present invention; the bellows, thespaces between the corrugations Fig. 2 is an enlarged fragmentarysection of a and fins are solidly filled with the oil, and therebellowsto show the damping elements in position; fore before movement of thebellows by way of Fig. 3 is a diagrammatic view to illustrate theexpansion or contraction can occur it is necesmanner in which thedamping elements are inisary that the oil in the intercorrugatlon spacestially assembled with the tube before corruga between the fins bedisplaced from said spaces, tion; if contraction of the corrugations isto be per- Fig. 4 is a diagrammatic view on a larger scale mitted, orthat oil fiow intosaid spaces, if expanto illustrate the first step inintegrating the dampsion of the corrugations is to be permitted againsting elements with the tube; the effort to create a vacuum. The flow ofoil Fi 5 is a correspon n view but illustrating into or out of theintercorrugation spaces, as a subsequent step in the integration of thedampthese spaces are increased or decreased in volume ing elements withthe corrugations; b the expansion or contraction of the bellows,

12 Claims. (Cl. 1 13-118) 2 Figs. 6 to 10, inclusive, are diagrammaticviews illustrating successive steps in the formation of a dampingelement; and

Figs. 11 to 15, inclusive, are corresponding views 3 therefore requiresan appreciable period of time depending upon the rate of flow of the oilas determined by the clearance existing between the periphery of theline II and the confining wall ll. By nicely predetermining thisclearance the rate of oil now and therefore the resistance to expansionor contraction of the corrugations can be accurately predetermined. Thuseach corrugation provided with a flu acts in the nature of a dash potand resists any tendency to vibrate at a relatively high frequency.Tests on structures of this type have shown that a considerablyincreased life has been given to a bellows subjected to a vibrationaltendency, the vibration having been largely damped out owing to the dashpot action of the fins. As the flow of oil into and out of theintercorrugation spaces eil'ects a positive and uniform retardation ofresponse to vibrational tendencies the damping action is eflectedwithout the irregularities which arise when friction is used to dampvibration.

While a bellows constructed to effect damping as herein disclosed may bemade in any suitable way, the present invention involves a novel methedwhereby such a damping bellows may be produced.

The fins used in damping the bellows may be made in any suitable way,the preferred procedure being shown in Figs. 11 to 15, inclusive, theproduct or the several steps being illustrated in Figs. 6 to 10,inclusive, respectively. As here shown, a disk of thin metal having thepredetermined diameter appropriate for the finished fin is cut fromsheet stock, as by a punch 3| cooperating with a die 32. The centerportion of disk 3| is then cut out as shown at 33 in Fig. 'l. as by apunch 3| cooperating with a piercing die 38, the inner diameter of theaperture 33 being such that when the inner periphery of the annulus soformed is shaped as next to be described the center aperture will make aclose sliding fit with the exterior of the tube to be corrugated. Theannular disk 30 is then flanged at its inner periphery as shown at 38 inFig. 8, as by a punch 38 cooperating with a forming die 40, and saidflange s8 is then bent outwardly as shown at ll in Fig 9, as by a secondforming punch 42 cooperating with a forming die 43. Flange 30 is thenbent into the substantially semicircular form as shown at 44 in Fig. 10,as by a further forming punch 45 cooperating with a forming die 46. Itis to be understood that Figures 6 to 15, inclusive, are diagrammaticonly, no efiort having been made to properly proportion the size of thedisk to the size of the reversely curved bend produced at the innerperiphery of the annulus formed. When completed, the fin has at itsinner periphery a reverselybent portion substantially in the form of asemicircular curve, the radius of curvature of which is such that saidreversely bent portion will snugly fit the inner periphery of a formingring as shown in the enlarged sections of Figs. 4 and 5.

Assuming, as is preferred, that all of the corrugations are to have finsintegrated therewith, the tube (Fig. 3) which is to be corrugated hasmounted thereon and equally spaced therealong aplurality of fins 2|corresponding in number with the corrugations to be formed, the spacingof the fins corresponding with the amount of metal that is to go intoeach corrugation.

The corrugating operation by which the fins are integrated with thebellows as the corrugations are formed is illustrated in Figs. 4 and 6.As here shown, each forming ring 5! has mounted thereon and snuglydtting its curved inner egtresnity I! a an it asheretofos'e described.The

into each commotion as understood in the hydrostatioally oorrugatingtubes to produce bellows.- Hydrostatic pressure is then introduced intothe tube II. and the tube is bulged between the forming rings II to lockthe fins ii in the depressions it between the bulges. The spacers I! arethen withdrawn and the corrugation of the tube is completed byhydrostatic pressure in a manner well understood in the art, anintermediate stage in the formation of the corrugations beingillustrated in Fig. 5. The corrugating operation being completed. thefins 2| assume the relationship to the completed corrugations II whichis shown on an enlarged scale in the fragmentary section of Fig. 2wherein each fin is in face contact with one of the parallel walls of acorrugation.

It will therefore be perceived that the method of providing the bellowswith dampin fins as described involves no mechanical attachment orconnection of the fins to the metal of the bellows to in any wayinteriere with the normal characteristics of the metal in the bellowsfolds as respects its capacity to bend and to respond to elastic forces.At the same time the fins are actually integrated into the bellowsstructure and cannot become cooked or displaced with respect theretobecause they are firmly held against displacement by reason of thecurved inner flanges of the fins snugly fitting the curved inner bendsof the corrugations.

It will therefore be perceived that by the present invention a novelmethod of making a damping bellows has been provided whereby withoutaltering the resilient and bending characteristics of the bellows metalthe damping elements have been securely integrated into the bellowsstructure against undesired displacement. The method of producing thebellows is one that can be readily carried out in apparatus forhydrostatically producing bellows now in use and without altering themethod of producing bellows hydrostatically. and the resulting bellowswith its damping elements can be produced expeditiously andinexpensively to provide a damped bellows which is certain and regularin operation.

While the method of the invention has beendescribed with particularity,it is to be expressly understood that the invention is not limitedthereto as changes in details of procedure and in the details ofconstruction will now be readily apparent to those skilled in the artwithout ,departing from the spirit of the present invention. Thus thefins may have configurations other than circular and other shapes,constructions and forms of damping elements may be used, all as will nowbe apparent to those skilled in the art, without departing from thespirit of the present invention. Reference is therefore to be had to theappended claims for a definition of said invention.

What is claimed is:

1. The method of making a damping bellows which includes the steps offormingannula'r fins having inner extremities curved to conform with theinner bends of the bellows wall to which said fins are to be attached,mounting said fins on the periphery of a tube to be corrugated, andlocking said fins to the tube by forming cormgaticns in said tubebetween said fins with the a l-sales inner bends of said corrugationsfitting the curved inner extremities of said fins.

2. The method of making a damping bellows which includes the steps offorming annular fins, mounting said line on the periphery of a tube tobe corrugated, bulging the tube between said fins to lock the fins tothe tube, and converting the bulges into parallel walled corrugationshaving face contact with said fins.

3. The method of making a damping bellows which includes the steps offorming annular fins having curved inner extremities conforming to thecurvature of the inner bends of the corrugations to be formed, mountingsaid fins on the periphery of a tube to be corrugated, bulging the tubeby hydrostatic pressure between the fins to lock said fins in position,and subjecting the tube to hydrostatic pressure to form said bulges intocorrugations contacting said fins both at the curved inner extremity andat the face of the fin.

4. The method of making a damping bellows which includes the steps offorming annular fins having inner peripheries curved to fit the inneredges of the forming rings of a hydrostatic corrugating machine,mounting said fins on said forming rings, and hydrostatically formingcorrugations in a tube mounted in said rings to bulge said tube betweensaid fins and lock said fins between said corrugations.

5. The method of making a damping bellows which includes the steps offorming annular fins having inner peripheries to fit the inner edges ofthe forming rings of a hydrostatic corrugating machine, mounting saidfins on said forming rings, spacing said forming rings uniformly byinterposed spacers, locking said fins to a tube to be corrugated bybulging the tube between said rings, withdrawing said spacers, andcompleting the corrugations around said fins.

6. The method of making a damping bellows which includes the steps offorming annular fins having inner peripheries curved to fit the inneredges of the forming rings of a hydrostatic corrugating machine,mounting said fins on said forming rings, locking said fins to a tube tobe corrugated by bulging the tube between said rings while said fins aremounted thereon, and converting said bulges into corrugations.

7. The method of making a damping bellows which includes the steps offorming fins each having a central aperture surrounded by an annularflange which is axially curved to conform with the irmer bends of thecorrugations to be formed, mounting said fins on the tube to becorrugated, and forming corrugations in said tube with their inner bendscurved into face contact with the surfaces of said flanges to lock thefins against relative movement while leaving the corrugation bends freeto flex upon expansion of the bellows.

8. The method of making a damping bellows which includes the steps offorming fins each having a central aperture surrounded by an annularflange which is axially curved to conform with the inner bends of thecorrugations to be formed, mounting said fins on die rings with theirannular flanges embracing the inner periphery thereof, and formingcorrugations in said tube with their inner bends curved into facecontact with the surfaces of said flanges to lock the fins 9. The methodof making a damping bellows which includes the steps of forming finseach having a central aperture surrounded by an annular flange which isaxially curved to conform with the inner bends of the corrugations to beformed, mounting said fins on the tube to be corrugated, and formingcorrugations in said tube with their inner bends curved into facecontact with the surfaces of said flanges by bulging the tube betweenthe fins to lock the fins against relative movement while leaving thecorrugation bends free to flex upon expansion of the bellows.

10. The method of making a damping bellows which includes the steps offorming fins each having a central aperture surrounded by an annularfiange which is axially curved to conform with the inner bends of thecorrugations to be formed, mounting said fins on die rings with theirannular flanges embracing the inner periphery thereof, and formingcorrugations in said tube with their inner bends curved into facecontact with the surfaces of said flanges by bulging the tube betweenthe fins to lock the fins against relative movement while leaving thecorrugation bends free to flex upon expansion of the bellows.

11. The method of making a damping bellows which includes the steps offorming fins each having a central aperture surrounded by an anularflange which is axially curved to conform with the inner bends of thecorrugations to be formed, mounting said fins on the tube to becorrugated, and forming corrugations in said tube with their inner bendscurved into face contact with the surfaces of said flanges by bulgingthe tube by hydrostatic pressure between the fins to lock the finsagainst relative movement while leaving the corrugation bends free toflex upon expansion of the bellows.

12. The method of making a damping bellows which includes the steps offorming fins each having a central aperture surrounded by an annularflange which is axially curved to conform with the inner bends of thecorrugations to be formed, mounting said fins on die rings with theirannular flanges embracing the inner periphery thereof, and formingcorrugations in said tube with their inner bends curved into facecontact with the surfaces of said flanges by bulging the tube byhydrostatic pressure between the fins to lock the fins against relativemovement while leaving the corrugation bends free to flex upon expansionof the bellows.

JEAN V. GIESLER.

REFERENCES CITED The following references are of record in the file. ofthis patent:

UNITED STATES PATENTS

